Adjustable boat chair



FIG. 1 is rear perspective view showing the features of the adjustable boat chair with the cushion in an exploded condition; and,

FIG. 2 is a rear perspective view showing the features of the adjustable boat chair with the cushion in the installed condition.

The left side of the adjustable boat chair is a mirror image of that shown in FIGS. 1 and 2. The portions of the adjustable boat chair as seen from the front which are not shown in the drawing views form no part of the claimed design. 

The ornamental design for an adjustable boat chair, as shown and described. 